Valve grinder



G. R- RICH VALVE GRINDER Nay. 22, 1927, 1,650,389

Fi led Feb. 5, 1927 Patented Nov. 22, 1927.

UNITED STATES GEORGE E. RICH, 0F BATTLE CREEK, MICHIGAN.

VALVE GRINDER. I

Application filed February This invention relates to valve grinders and its principal object is to provide im-- proved means whereby the tapered seating. face poppet valves for internal combustion engines may be ground more nearly to a perfect circle than has been done heretofore.

As is well understood, the tapered seating face of poppet valves, seat upon corre spondingly tapered valve seats formed in the cylinders of internal combustion engines, and unless the valves seat perfectly, leaks occur between the valve and its seat, thereby causing poor compression and loss of power. Considerable difficulty has been encountered in attempting to accurately grind the tapered seating face of the valves, and this is due to many causes that cannot be avoided, for instance when the headed I to the shaft 7 is the mechanism which holds end of the valve is held on a centre in grinding the valve, the centre may be off centre with respect to the axis of the valve, with the result that the tapered seating face is ground off centre. Frequently the collet which holds the valve stem becomes worn and loose, and the valve is thereby caused to wabble, or chatter or rotate bodily around a true centre, whereby the-resulting work is inaccurate.

In accordance with the present invention I provide a solid, substantial valve holder,

with means for holding the valve against any wabbling, chattering or-bodily rotation around a centre, whereby the'tapered seating face thereof may be accurately ground, and whereby none of its tapered seating face will be appreciably out of a true circle.

The invention consists, therefore, in a valve grinder having means for rotating the valve, and a rigid valve holder having a bore'for receiving the stem of the valve and a spring pressed pressure block engaging the side of the stem and firmly holding said stem against one side of said bore during the grinding operation. It further consists in the several novel features hereinafter fully set forth and claimed.

The invention is clearly illustrated in the drawings accompanying this specification, in which:

Fig. 1 is a plan of a valve grinder embodying a simple form of the present invention, the grinding tool being partly broken away; Fig. 2 is an end elevation looking in the direction of the arrow 2 in Fig. 1, of the valve holder which forms part of the invention; Fig. 3 is a view, partly in plan and partly a; 1927. Serial No. 165,551.

in horizontal section of the valve holder and adjacent parts, the line of section being shown at 3-3 in-Fig. 2; Fig. 4; is a perspective view of a bushing employed in the valve holderand centering device and Fig. 5 is an end view of onevof thevalvcs on which the grinding is done by the machine.

Referring toisaid drawing, which illustrates a simpleembodiment of the present invention, the reference character 5 designates a grinding tool having the usual grind-- ing wheel 6 which is carried by a shaft 7 mounted in a bearing member 8 that is movable lengthwise and crosswiseof itself as usual. A pulley 9 on the shaft 7 is belted to a suitable power-pulley and furnishes means for rotating the grinding wheel 6.

- Extending at a suitable angle withrespect one end of the head] The chuck contains a collet-13, the jawsof which grip the valve stem'as usual. The chuck 12 is connected to a pulley 14 whereby the chuck and its collet may be rotated, and a handle 15, is provided which is operatively connected to the collet and furnishes the means for clamping the jaws of the collet upon the valve stem and unclamping them therefrom. The collet has a tapered face as usual engaging with a tapered face in the end of the chuckbody and by drawing the collet against said tapered face of the chuck body the collet is clamped upon the valve "stem.

All of the'mechanism thus far described is common and well known and requires no further description so far as this specification is concerned. The Valve rotating mechanism operates to rotate the valve on its longitudinal axis at the proper angle to the grinding face of the grinding wheel 6, and

in grinding the seating face of the valve the grindlng wheel 1s brought into, contact with the seat ngface and the grinding operation is continued until completed. It will be un- Iii derstood that prior to the operation of grinding the tapered seating face of the valve, its stem has been ground true. Supported upon the base 11 at a placein co axial alignment with the chuck 12 and head 10, is the valve holder 16. Said valve holder comprises a solid post 17 having a foot 18 which is fastened to the base 11 by bolts or other fastening devices. The post 17 is bored out at 19 to receive a bushing 20 which contains a bore or hole 21 therethrough which is concentric with the axis of the chuck, and is of a diameter to receive the stern a, of a poppet valve A. The clearance between the bushing and the valve stem should be only suliicient to permit the stem to be inserted into the bore and turn freely therein. In the sides of the post'li' and bushing 20 adjacent the grinding wheel are cut away portions which form registering notches 22, 22, in which is located a pressure block 24 that is spring pressed toward the bore of the bushing by a strong spring 23, preferably in the form of a fiat spring secured to the side of the post 17 and block Conveniently the upper end 26 of the flat spring forms a handle by 24 by screws 25.

jaws of the collet 13, and clamped in place therein. As soon as the spring 23 is released 1t forces the pressure block 2d against the side of the valve stem and forces the ovalvesteni snugly against the opposite side of the bore 21, in the bushing. The spring 23 has suificient tension to firmly hold the valve stem against said side of the bore and thereby prevent any wabbling or chattering of the stern, thereby compelling its surface to follow a true circular course. The grinding wheel is then moved up to the tapered seating face a of the valve head a and said face is ground in the usual manner. When finished the spring 23 is drawn back and the valve removed from the valve holder.

With the use of a device containing the herein described invention the tapered seating faces of poppet valves are ground very accurately. Measured with very delicate measuring instruments the tapered'seating faces of valves ground by the present device are found to vary less than one thousandth part of an inch out of true. Furthermore the necessity of formmg centers in the valve heads iseliminated, the work of grinding 7 claims to point out all of the invention disclosed herein.

I claim as new, and desire to secure by' Letters Patent:

1. In a valve grinder, the combination with a rotating grinding wheel and. a rotating chuck, having a collet arranged to grip the stem of a popnet valve, of a valve holder and centering dev; comprising a rigid post mounted adjacent said grinding wheel and having a bore, in alignment with said chuck, for the reception of the valve stem, and there being a recess in the side of said block, and a spring pressed pressure block entering said recess and adapted tobear against the side said stem and forcibly hold the stem in contact with a side of said bore, said pressure block having a handlewhereby it may be retracted from the stem of the valve.

In a valve grinder, the combination with a rotating grinding wheel and a rotating chuck, having a collet arranged to grip the stem of a poppet valve, of a valve holder and centering device having. a rigid post, and mounted adjacent said grinding'wheel, a bushing therein arranged in alignment with said chuck, said post and bushing hav ing aligned recessed portions therein, a pres sure block entering through said recess in' said post and bushing, and a spring engaging said block in a direction to force it against the side of a valve stem held in said bushing, there being a handle on said block whereby it may be retracted from said valve stem.

3. in a valve grinder, the combination of a rotating grinding wheel, a rotating chuck arranged at an oblique angle to the rinding edge of said grinding wheel, a ri d post mounted adjacent said grindi g wheel and having a bushing moun ment with said chuck,

there being aligned recesses in said post and. bushing and a spring pressed pressure block entering said bushing through said recess, said pressure block being arranged to press against the side of a valve stem held in said bushing, and having a handle whereby the block may be retracted from the valve stem.

Gnonsn a. men.

d in ce axial align-' Bil 

